[SOLVED] CPU Overheating - Cant find the culprit

[IceTokki]

So I noticed my CPU overheating to 100C and have been trying for days to figure out what it is. Here's what I know:

Parts:

• CPU: Intel i7 9700K (not overclocked, purchased new 2019)
• Mobo: MSI Z390-A Pro (purchased new 2019)
• Cooler: NZXT Kraken X53 (purchased 2 days ago to possibly solve this issue) (Old liquid cooler was a Corsair something or other)
• Corsair 750W PSU (purchased new 2019)

Observations:

• PC seemed to stream and run games like Phasmophobia just fine before last Friday
• Friday my stream while playing Phasmophobia was super laggy, despite no dropped frames in stream or noticeable dropped frames in game
• Noticed the temperature of the CPU was hitting 100C (temps of everything else close to room temp)
• Temperature in BIOS currently also 100C (idle), indicating hardware issue not software
• Old cooler's tubes were hot, indicating the cooler was working
• New cooler's tubes were not hot, despite the water block feeling warm to touch
• New cooler light was on when running, fans also running, indicating SATA cable was probably working fine
• I can feel slight vibration of the new cooler's tubes, indicating there is circulation
• All air being blown is cool air, not warm or hot
• CPU usage is between 1%-5% (idle)
• Voltage around 0.6 consistently
• A few weeks ago I plugged a small USB light into the Front USB port of the tower and got blue screened while on stream and PC restarted

Attempted Solutions:

• Checked CPU for dust and cleaned out
• Check all fans working (they are & with great air flow)
• Checked mount security of the water block (it's secure)
• Replaced water cooler
• Replaced thermal paste
• Restarted PC
• Switched the CPU fan with the pump fan connections, all I noticed was the tube vibration had stopped. Switched back after.
• Tried a third water cooler (corsair H100i)
• Replaced CPU (i9 9900k)
• Switched out SSD with another PC's HDD, just in case it was a virus
• Updated BIOS

The only conclusion I have is somehow the motherboard is causing the CPUs to overheat? Is that possible? Idk what else it could possibly be. Plz halp <3

 

[rgd1101]

Does the temp go high during benchmark?
could be a bad sensor on the motherboard

 

[IceTokki]

Does the temp go high during benchmark?
could be a bad sensor on the motherboard

Ran a stress test and it went up from 54C and quickly climbed up to 100C after less than a minute. The CPU is getting hot because the coolers are warm to touch, but obviously I can't tell exactly how hot just by touch.

You very well could be right about the sensor. I ordered a new motherboard as a last solution. But if it is the mobo, then how is it reading steady temperature climbs between turning on the pc, running idle, and opening games, etc? Wouldn't it just read a wonky arbitrary temperature?

 

[IceTokki]

UPDATE:

Brand new motherboard installed and temperature instantly went up to 84-90C.

At this point I have no idea what's causing it. I'm going to get a new PSU next I guess.

 

[rgd1101]

since you replace everything else. yeah, try a new psu

 

[grimfox]

If the tubes are cold and the radiators are cold then fluid isn't flowing. Pump is not working. Not sure where the vibration is coming from but to me it's the pump. You've already eliminated the cooler, the CPU, and the mobo, by changing those out. Don't need to go after the PSU...That's just not something that can cause high temps. Have you been using the same SATA port to power the the various coolers? It's possible that port is damaged and no longer working/ providing power, or enough power to properly drive the pump.

Could also be a software issue. What are you using to control and read the pump speed?

In your shoes I would have gone to a basic air cooler, just as a sanity check.

 

[IceTokki]

UPDATE/SOLVED

So I finally found a local place to run diagnostics and 2 different things were broken:

The old liquid cooler had broken and fried the i7 processor. So when I replaced the cooler, the CPU was still defective and returned high temperatures. Then I replaced the CPU, but the new cooler I bought was DEFECTIVE UPON ARRIVAL, which caused then new i9 CPU to overheat as well, and produce similar results. What are the odds......

Both mobos are fine though, and the i9 CPU is not damaged because I didn't have it running for extended periods. So I've replaced the liquid cooler with a high quality air cooler and all is well - idle temperatures read about 30C and high intensity loads render it around 70C.

Thank you everyone for your help <3

 

[IceTokki]

If the tubes are cold and the radiators are cold then fluid isn't flowing. Pump is not working. Not sure where the vibration is coming from but to me it's the pump. You've already eliminated the cooler, the CPU, and the mobo, by changing those out. Don't need to go after the PSU...That's just not something that can cause high temps. Have you been using the same SATA port to power the the various coolers? It's possible that port is damaged and no longer working/ providing power, or enough power to properly drive the pump.

Could also be a software issue. What are you using to control and read the pump speed?

In your shoes I would have gone to a basic air cooler, just as a sanity check.

Yeah this was the most correct/helpful answer - see the updated solution but basically the cooler was bad out of the box >.<